Focusing device for electric lamps



A. 5. LYHNE.

FOCUSING DEVICE FOR ELECTRIC LAMPS. APPLICATION FILED FEB. 12, 192l.

1,408,528 Patented Mar. 7, 1922.

INVENTOR A'TTORNEY area mm ANKER S. LYHNE, OF BRIDGEPORT, CONNECTICUT.

' EOCUSING DEVICE FOR ELECTRIC LAMPS.

Specification of Letters Patent.

Patented Mar. 7, 1922.

Application filed February 12, 1921. Serial No. 444,595. I

which the following is a specification.

This invention relates to flashllghts and- 'more particularly to meansfor focussing the light with regard to the reflector. Hitherto it hasbeen common practice to make casings for flashlight batteries carryingat one end a reflector with a lamp secured in a permanent socket in thereflector, thereby allowing no provision for moving the lamp with regardto the reflector and consequently not permitting any alteration in thefocussing of the lamp. .As lamps are made in various designs thefilament is not always in the exact position required for proper focus,and the result is in such lamps a failure to obtain the best resultsfrom the reflector. To overcome this difficult I have devised a form offlashlight in wliich the position of the lamp with regard to thereflector is easily adjustable. My invention is embodied in the devicedescribed in the following specification and illustrated in theaccompanying drawing, of which Figure 1 is a side View showing certainparts in sectlon;

-Figure 2 is a half section and half side view of the assembled lamp andreflector showing a modified form of adjusting nut;

Figure 3 is a cross-section on the line III- III of Figure 2; and

Figure 1 is a perspective view of the assembled flashlight.

1 denotes a casing for the battery which is made in two parts, 2 and 3,connected at 4. Casing member 3 is flared at one end as at 5 to receivethe reflector 6. Lamp 7 is secured within bushing 8 which is hollow andinternally threaded to receive the lamp. Bushing 8 is also externallythreaded,the threads and a portion of the bushing being 7 squared off ontwo sides 9, as shown in Figwe 3, to prevent the bushing from rotating.Reflector 6 is provided with a central orifice shaped to conform to thecross-section of the bushing so as to permit the latter to movelongitudinally therein. Bushing 8 has a collar 10 adjacent the endwithin the reflector 6. Collar 10 may be integral with bushing 8 or maybe securely fixed thereto by welding or other suitable means. A nut 11engages the external threads onbushing 8. A helical spring 12 surroundsbushing 8 between collar 10 and reflector 6. The perlphery of nut 11, asshown in Figure 2, is knurled to provide for manual adjustment ofthenut.

In Figure 1 is shown a modified means for adjusting the nut 11 when thelamp and reflector are assembled within casing 1. Integral with nut 11is a disc 20 provided on 1ts periphery with gear teeth 13. Secured inthe side of easing member 3 is a bushing 14 within which rotates a shaft15 having gear 16 on its inner end and having a knurled disc 17 on itsouter end for adj usting, the gear 16 meshing with gears 13.

Means are provided for grounding the outer terminal or the shell of thebattery in casing 1 through a switch 18 carried on casing member 2.Reflector 6 and bushing 8 complete the circuit between the threads ofthe lamp and casing 1, while the central contact of the lamp is directlyin contact with the central pole of the battery as at 19. A spring (notshown) in the lower end of casing member '2 maintains the central poleof the battery always in contact with the central contact of the lamp.

The operation of the device is obvious. In addition to the advantage ofconvenient focussing, this invention affords a spring seating for thefragile lamp, cushioning it against shock and protecting it both in useand in shipment. The arrangement shown in Figure 1 permits readyadjustment of focus without removing the reflector 6, which wouldnecessitate removal of the usual threaded cap and lens.

In the foregoing description it is assumed that casing 1 is made ofconducting ma terial. Where it is desirable to make the casing anon-conducting material, it is a simple matter to complete the circuitby providing conducting strips between the terminals which otherwisewould be grounded in the casing.

Vhat I claim is:

1. In combination with a source of illumination and a reflector,focussing means comprising an externally threaded bushing partiallysquared oil to prevent rotation and carrying said source ofillumination, said reflector having an orifice conforming to thecross-section of the bushing and permitting longitudinal motion of thebushing therethrough, a collar on the bushing on one side of saidorifice, a nut threaded on the bushing on the opposite side of saidorifice, and a spring around said bushing between said collar and saidreflector, for holding said nut against the latter.

2. In combination, a reflector provided with an opening therein, anexternally threaded lamp support mounted and longitudinally movable insaid opening-said support and opening formed to 'coact to preventrotation of said support, a collar on said support on one side of thereflector, a nut threaded on said support on the other side of thereflector, and a spring between the reflector and said collar.

3. In a flashlight comprising a battery, a casing for the same, anincandescent electric lamp and a reflector secured to said casing,focussing means comprising a hollow bushing having internal and externalthreads, the former for carrying said lamp and the latter partiallysquared off to prevent rotation of the bushing, said reflector having acentral orifice conforming to the cross-section of the bushing andpermitting longitudinal motion of the bushing therethrough, a collar onthe bushing within the reflector, a nut threaded on the bushing betweenthe reflector and the battery, and a spring around said bushing betweensaid collar and said reflector for holding said nut against the latter,the central contact of the lamp being in contact with the central poleof the battery, and the casin being connected with the outer pole 0 thecompleting the circuit of said battery through said lamp, focussingmeans comprising a hollow bushing having internal and external threads,the former for carr ing said lamp and the latter partial y squared offto preventrotation of the bushing, said reflector having a centralorifice conforming to the cross-section of the bushing and permittinglongitudinal motion of the bushing therethrough, a collar on the bushingwithin the reflector, a nut threaded on the bushing between thereflector and the battery, a spring around said bushing between saidcollar' and said reflector for holding said nut against the latter, andmeans external to said casing for rotating said nut.

5. In a flashlight comprising a battery, an incandescent electric lamp,a reflector,and a casin for said battery and reflector, said casingaving a flared open end for securing said reflector therein, and meansfor. completing the circuit of said battery through said lamp, focussingmeans comprising a hollow bushing having internal and external threads,the former for carr ing said lamp and the latter artiall y squared offto prevent rotation of tlie bushing, said reflector having a centralorifice conforming to the cross-section of the bushingand ermittinglongitudinal motion of the bushing therethrough, a collar on the bushingwithin the reflector, a nut threaded on the bushing between thereflector and the battery, a spring around said bushing between saidcollar and said reflector for holding said nut against the latter, saidnut having ear teeth, and geared means meshing wit said teeth andextending through said casing for rotating said nut from the outside.

In testimony whereof I affix my si ature.

ANKER S. LY NE.

